The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a method and system for repairing turbomachine dovetail slots.
Turbomachine systems typically include a turbomachine coupled to an intake system and a load. The turbomachine typically includes a compressor portion and a turbine portion. An airstream passes through the intake system into the compressor portion. The compressor portion forms a compressed airstream that is introduced into the turbine portion. In a gas turbomachine, a portion of the compressed airstream mixes with products of combustion in a combustor assembly forming a hot gas stream that is introduced into the turbine portion through a transition piece. The hot gas stream flows along a hot gas path interacting with various components of the turbine portion.
Both the compressor portion and the turbine portion include rotors that support a plurality of airfoils. In some cases, the airfoils are connected to the rotor through a dovetail joint. More specifically, the airfoil may include a pin and the rotor may include a tail or slot. Occasionally, cracks may develop in the rotor at the slot as a result of low cycle fatigue caused by alternating stresses generated through thermo-mechanical load. A percentage of the cracks that develop may be repaired. A repair often requires removal of the rotor from the turbomachine and mounting to a computer controlled milling machine. Typically, a computer controlled milling machine is not available on site. Thus, after removal, the rotor is shipped off-site for repair. Accordingly, cracks may lead to prolonged downtime for the turbomachine.